Review on Mn-based and Fe-based layered cathode materials for sodium-ion batteries

Sodium-ion batteries are widely studied due to their abundant sodium resources, widespread distribution, and environmental friendliness. However, due to the large radius of sodium ions, during the charge and discharge process, the cycling performance and rate performance deteriorated seriously, which severely limited the commercial application of sodium-ion batteries. The positive electrode material plays a vital role in the performance of sodium-ion batteries. NaxFeO2 and NaxMnO2 series positive electrode materials showed high theoretical specific capacity and environmentally friendly. They are considered to be potential positive electrode materials for sodium-ion batteries. This article summarizes the research progress of NaxFeO2 and NaxMnO2 series cathode materials in recent years, and discusses the problems and development directions of cathode materials for sodium-ion batteries.